Safety Study of Photodynamic Therapy Using Talaporfin Sodium in the Pancreas and Surrounding Tissues in the Syrian Golden Hamster

Abstract EN

Aim.

To assess the safety of photodynamic therapy (PDT) using talaporfin sodium on the pancreas and surrounding organs in normal hamsters.

Methods.

Fluorescence microscopy documented talaporfin levels in liver, duodenum, and pancreas up to 24 hours after photosensitisation.

Lesion size in liver 3 days after PDT (50 J, 5 mg/kg, variable drug-light interval (DLI)) was documented to optimise the DLI.

Using optimum DLI, pancreas and surrounding organs were treated with laser fibre touching the surface and animals were killed at 3 or 21 days.

Results.

Peak fluorescence was seen in duodenum and pancreas at 15 mins (second lower peak at 2 hours).

Liver fluorescence was consistently high (peak 1 hour) until after 4 hours.

Optimum DLI was seen at 15 minutes.

The pancreas was relatively resistant to direct PDT injury (small lesions at high doses) but surrounding stomach, duodenum, and liver were more susceptible with evidence of adhesions and full thickness damage (localised peritonitis and duodenal perforation at highest doses).

Conclusion.

The safety profile is similar to PDT with longer acting photosensitisers.

The pancreas appears safe to treat, but care is required to avoid high light doses to the intestinal tract, particularly the duodenum.